A British-flagged oil tanker, which had been detained by Iran has set sail, a specialist shipping website said.

:: A British-flagged oil tanker, which had been held off the Iranian port of Bandar Abbas for more than two months, has set sail, a specialist shipping website reported on Tuesday.

Government spokesman Ali Rabiei had announced on Monday that “the legal process has finished” and the Swedish-owned vessel was free to leave.

“This morning’s satellite imagery captured by @planetlabs reveals that the #StenaImpero is NO LONGER ANCHORED at this location (27.07° N, 56.25° E),” TankerTrackers.com said on its Twitter account.

“She has been there since the second week of August.”

Stena Bulk, the company that owns the tanker, said on Sunday that it expected the vessel to be released soon, but had expressed caution about the situation.

Stena Bulk CEO Erik Hanell had said that the tanker is still in the country despite Iranian officials saying it was free to leave.

“She has moved during her time there to get fresh water, among other things, but is still in Bandar Abbas,” Hanell said in a text message, adding he had no information as to why the ship had not left Iran.

The seizure of the Stena Impero on July 19, two weeks after Britain detained an Iranian tanker off Gibraltar, ratcheted up tensions in the region following attacks on other merchant vessels which Washington blamed on Tehran.

Iran denied responsibility for those attacks, which took place along a vital international oil shipping route.

An Iranian government spokesman said on Monday that all legal steps had been completed for the release of the tanker, Iranian media reported.

“The legal work and administrative procedures for the release of the English tanker have been completed but I have no information on the time of the release,” said spokesman Ali Rabiei, according to semi-official news agency ILNA.

Relations between the US, its allies and Iran have become more strained since Washington withdrew last year from a global pact aimed at reining in Tehran’s nuclear program and imposed sanctions on it aimed at shutting down Iranian oil exports.